Species Evolution: The Role of Chromosome Change.

AbstractUnderstanding the relative influence of various abiotic and biotic variables on diversification dynamics is a major goal of macroevolutionary studies. Recently, phylogenetic approaches have been developed that make it possible to estimate the role of various environmental variables on diversification using time-calibrated species trees, paleoenvironmental data, and maximum-likelihood techniques. These approaches have been effectively employed to estimate how speciation and extinction rates vary with key abiotic variables, such as temperature and sea level, and we can anticipate that they will be increasingly used in the future. Here we compile a series of biotic and abiotic paleodatasets that can be used as explanatory variables in these models and use simulations to assess the statistical properties of the approach when applied to these paleodatasets. We demonstrate that environment-dependent models perform well in recovering environment-dependent speciation and extinction parameters, as well as in correctly identifying the simulated environmental model when speciation isenvironment-dependent. We explore how the strength of the environment-dependency, tree size, missing taxa, and characteristics of the paleoenvironmental curves influence the performance of the models. Finally, using these models, we infer environment-dependent diversification in three empirical phylogenies: temperature-dependence in Cetacea,δ13C-dependence in Ruminantia, andCO2-dependence in Portulacaceae. We illustrate how to evaluate the relative importance of abiotic and biotic variables in these three clades and interpret these results in light of macroevolutionary hypotheses for mammals and plants. Given the important role paleoenvironments are presumed to have played in species evolution, our statistical assessment of how environment-dependent models behave is crucial for their utility in macroevolutionary analysis.

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Deep and wide valleys drive nested phylogeographic patterns across a montane bird community

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2015.0861 ◽

2015 ◽

Vol 282 (1810) ◽

pp. 20150861 ◽

Cited By ~ 23

Author(s):

V. V. Robin ◽

C. K. Vishnudas ◽

Pooja Gupta ◽

Uma Ramakrishnan

Keyword(s):

Bird Community ◽

Mountain Range ◽

Climatic Fluctuations ◽

Tropical Mountain ◽

Palghat Gap ◽

Spatial Concordance ◽

Species Evolution ◽

The Western Ghats ◽

Range Fragmentation

Montane species distributions interrupted by valleys can lead to range fragmentation, differentiation and ultimately speciation. Paleoclimatic fluctuations may accentuate or reduce such diversification by temporally altering the extent of montane habitat and may affect species differentially. We examined how an entire montane bird community of the Western Ghats—a linear, coastal tropical mountain range—responds to topographic valleys that host different habitats. Using genetic data from 23 species (356 individuals) collected across nine locations, we examined if different species in the community reveal spatial concordance in population differentiation, and whether the timing of these divergences correlate with climatic events. Our results reveal a nested effect of valleys, with several species (10 of 23) demonstrating the oldest divergences associated with the widest and deepest valley in the mountain range, the Palghat Gap. Further, a subset of these 10 species revealed younger divergences across shallower, narrower valleys. We recovered discordant divergence times for all valley-affected montane birds, mostly in the Pleistocene, supporting the Pliestocene-pump hypotheses and highlighting the role of climatic fluctuations during this period in driving species evolution. A majority of species remain unaffected by valleys, perhaps owing to geneflow or extinction–recolonization dynamics. Studying almost the entire community allowed us to uncover a range of species’ responses, including some generalizable and other unpredicted patterns.

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Species evolution: The role of chromosome changeby Max King Cambridge University Press, 1993. £40.00/$59.95 (xix + 322 pages) ISBN 0 521 35308 4

Trends in Genetics ◽

10.1016/0168-9525(94)90020-5 ◽

1994 ◽

Vol 10 (1) ◽

pp. 34-35

Author(s):

Gabby Dover

Keyword(s):

Cambridge University ◽

Species Evolution

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Chromosome Stability of Synthetic-Natural Wheat Hybrids

Frontiers in Plant Science ◽

10.3389/fpls.2021.654382 ◽

2021 ◽

Vol 12 ◽

Author(s):

Laibin Zhao ◽

Die Xie ◽

Chaolan Fan ◽

Shujie Zhang ◽

Lei Huang ◽

...

Keyword(s):

Common Wheat ◽

De Novo ◽

Recombinant Inbred Lines ◽

Chromosome Instability ◽

Wheat Variety ◽

Chromosome Variation ◽

Synthetic Wheat ◽

Species Evolution ◽

Wheat Hybrids

Primary allopolyploids are not only ideal materials to study species evolution, but also important bridges in incorporating genetic diversity of wild species into crops. Primary allopolyploids typically exhibit chromosome instability that a disadvantage trait in crop breeding. Newly synthesized hexaploid wheat has been widely used in wheat genetics and breeding studies. To better understand the cytological and genetic basis of chromosome instability, this study investigated the chromosomes of a large number of seeds derived from the synthetic wheat SHW-L1 and its hybrids with natural wheat. SHW-L1 exhibited persistent chromosome instability since we observed a high frequent chromosome variation de novo generated from euploid SHW-L1 plants at the 14th generation of selfing (F14). High frequent chromosome variations were also observed in the F2 hybrids and most of the analyzed recombinant inbred lines (RILs) at F14, derived from the cross of SHW-L1 with common wheat variety Chuanmai 32. Chromosome instability was associated with frequent univalency during meiotic metaphase I. The experiment on reciprocal crosses between SHW-L1 and Chuanmai 32 indicated that cytoplasm has not obvious effects on chromosome instability. An analysis on 48 F14 RILs revealed chromosome variation frequency was not associated with the Ph1 alleles from either SHW-L1 or Chuanmai 32, rejecting the hypothesis that chromosome instability was due to the Ph1 role of synthetic wheat. In the analyzed RILs, chromosome instability influences the phenotype uniformity, showing as obvious trait differences among plants within a RIL. However, the analyzed commercial varieties only containing ∼12.5% genomic components of synthetic wheat were chromosomally stable, indicating that chromosome instability caused by synthetic wheat can be effectively overcome by increasing the genetic background of common wheat.

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Active Passive

South Atlantic Quarterly ◽

10.1215/00382876-8795754 ◽

2021 ◽

Vol 120 (1) ◽

pp. 103-121

Author(s):

Daniel A. Barber

Keyword(s):

Solar Energy ◽

Technological Innovation ◽

Architectural Design ◽

Heat Storage ◽

History Of ◽

Species Evolution ◽

Passive Solar ◽

Solar House ◽

Resource Conditions

This essay proposes an inversion and productive complication of the familiar nomenclature of active and passive solar energy, as it pertains to architectural design methods and to solarity more generally: that is, to changes in economies, cultures, and ways of living in the present and future. I examine three houses central to the history of solar energy and its possible futures: the George O. Löf House (Denver, CO, 1957); the Douglass Kelbaough House (Princeton, NJ, 1974), and the Saskatchewan Conservation House (Regina, Saskatchewan, 1977) in order to assess the cultural and technical changes they elicited. At stake in reconsidering the distinction between active and passive solar energy is an attempt to understand how we experience simultaneously the resource conditions of our thermal interiors and the transformations of global climatic patterns. Which is to say, reconsidering active and passive in solar architecture (with heat storage as the hinge) also reconsiders the role of buildings in the production of the carbon zero future—less, at least relatively, as spaces of technological innovation, and more as spaces of social and species evolution. An active passive solar architecture aspires to lifestyles, habits, and expectations coming into line with the massive geophysical transformation of climate instability. By emphasizing the contingency of the built environment and of means of inhabitation, the solar house becomes a medium for epochal social change.

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A Cretaceous bug with exaggerated antennae might be a double-edged sword in evolution

10.1101/2020.02.11.942920 ◽

2020 ◽

Author(s):

Bao-Jie Du ◽

Rui Chen ◽

Wen-Tao Tao ◽

Hong-Liang Shi ◽

Wen-Jun Bu ◽

...

Keyword(s):

Sexual Selection ◽

High Efficiency ◽

Sensory System ◽

Sensory Organs ◽

Evolutionary Innovation ◽

Key Factor ◽

Opposite Sex ◽

New Type ◽

Species Evolution

AbstractIn the competition for the opposite sex, sexual selection can favor production of exaggerated features, but the high cost of such features in terms of energy consumption and enemy avoidance makes them go to extinction under the influence of natural selection. However, to our knowledge, fossil on exaggerated traits that are conducive to attracting opposite sex are very rare. Here, we report the exaggerated leaf-like expansion antennae of Magnusantenna wuae Du & Chen gen. et sp. nov. (Hemiptera: Coreidae) with more abundant sensory hairs from a new nymph coreid preserved in a Cretaceous Myanmar amber. The antennae are the largest among species of coreid and one of the largest known insects. Such bizarre antennae indicate that sensitive and delicate sensory system and magnificent appearance in Hemiptera have been already well established in mid-Cretaceous. Our findings provide evidence for Darwin’s view that sensory organs play an important role in sexual selection. This nymph with the leaf-like antennae may also represents a new camouflage pattern for defense. However, the oversized antennae are costly to develop and maintain, increasing the risks from predators. Such unparalleled expanded antennae might be the key factor for the evolutionary fate of this Myanmar amber coreid species.SignificanceDarwin proposed the importance of sensory organs in sexual selection, but it was greatly ignored compared with weapons and other common ornaments. Here, we report a new type of insect antennae, the multiple segments leaf-like expansion antennae from a new nymph coreid preserved in a Cretaceous Myanmar amber. Our finding provides evidence for the prominent role of sensory organs in sexual selection and thus supports Darwin’s viewpoint. This discovery demonstrates that high-efficiency antennae were present in Coreidae 99 million years ago. In addition, the exaggerated antennae might represent a new evolutionary innovation for defensive behavior. This is a case in which the high benefits and high costs brought by the exaggerated antennae jointly determine the direction of species evolution.

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